Abstract

Background: Urolithiasis in the pediatric population is about 10 times less common than among adults. Adolescents present with similar symptoms to adult patients, among them renal colic (acute, severe flank pain, which radiates to the groin). This case report shows an atypical course of retromediastinal tumor, which mimicked symptoms of renal colic.

Case presentation: A 15-year-old boy was admitted to Pediatric, Nephrology and Allergology Department, Military Institute of Medicine due to suspicion of urolithiasis. Patient presented left flank pain treated as renal colic. Before admission the boy was hospitalized in three centers during March 2016, July 2016 and September 2016. During those hospitalizations X-ray examination revealed a small calcification in the left kidney, however no renal calculi were detected in urography and repeated ultrasound examinations.

Discussion: Patient was treated twice with antibiotics (cefuroxime, amikacin) due to increased inflammatory parameters. Analgesics and antispasmodic drugs were administered almost continuously, without any significant effect on reported symptoms. At admission no stones were visible in ultrasound examination, therefore abdominal computed tomography (CT) was performed. No signs of urolithiasis were observed in the scan, however abnormal mass on the left-side of the chest wall was found. The study was extended to thoracic CT scan, which revealed a mediastinal tumor. Patient was referred to an oncology department where Ewing sarcoma/ primitive neuroectodermal tumor (PNET) was diagnosed in pathologic analysis.

Conclusion: Symptoms which mimic renal colic may not always be caused by urolithiasis. Even though posterior mediastinal tumors among children are significantly less common than renal stones, doctors should always consider all potential causes of symptoms that are reported by our patients. Ultrasonography remains the study of first choice, however CT should be recommended in patients with persistent symptoms of urolithiasis or nondiagnostic ultrasound examination.